Add user notes on accounts (#14148)

* Add UserNote model

* Add UI for user notes

* Put comment in relationships entity

* Add API to create user notes

* Copy user notes to new account when receiving a Move activity

* Address some of the review remarks

* Replace modal by inline edition

* Please CodeClimate

* Button design changes

* Change design again

* Cancel note edition when pressing Escape

* Fixes

* Tweak design again

* Move “Add note” item, and allow users to add notes to themselves

* Rename UserNote into AccountNote, rename “comment” Relationship attribute to “note”

config/locales/en.yml

@@ -940,6 +940,8 @@ en:
       redirect: Your current account's profile will be updated with a redirect notice and be excluded from searches
   moderation:
     title: Moderation
+  move_handler:
+    copy_account_note_text: 'This user moved from %{acct}, here were your previous notes about them:'
   notification_mailer:
     digest:
       action: View all notifications